That is great that you are doing this. Cause at the moment I had carried out biological research on the wave lengths and PAR wattage required (I just can't really convert enrgy of light in to photon flux). Apparently we do need leds higher than 640, especially wee must have 680nm and 700nm as theese wave lengths affect photosythetic rate and photomorphogenesis of the plant.
So these are the wave lengths I have discovered are preferable to have.

420
430
440
450
460

620
630
640
650
660
670
680
700

720 (optional)
We need to maintain approximately the same light energy power output on each wavelength.
Total light energy power should be around 350 Watts per meter sq (500 PAR (photosynthetic active radiation) watts for eqatorial sun).
Also you may have a look at my link in signature. There you may find spectras for chlorophyll a and b and carotenoids.